Luis H. Tello, MV, MS, DVM
Abdominal trauma is a common complication of multiple-trauma or could be a separated single issue; vehicle accidents, fights, penetrating injuries, falls, hunting dogs and "step-on" accidents with puppies, small dogs or cats are common causes for this condition.
The real challenge is trying to establish each case within 3 groups: Patients that require urgent surgical intervention after previous stabilization, medical conditions that do not require immediate surgical intervention, and other conditions that require only monitoring.
However, medical decisions about the management of these patients can only be made after establishment of an accurate diagnosis. A complete history and physical examination are the most important diagnostic tools for these patients. Physical examination should look for areas of possible external wounds or bruises; gentle palpation in order to identify areas of specific pain, apparent presence of free fluid, changes in size, symmetry and color of the abdomen. Dogs with intense abdominal pain may adopt aberrant posture as the "praying position" that helps them to alleviate the abdominal pressure and discomfort. Cats may stand with their heads extended and elbows abducted, similar to the posture adopted with respiratory distress.
As part of the immediate diagnostics approach, we currently recommend abdominocentesis, if the tapping is negative then peritoneal lavage and abdominal ultrasound (FAST). Chemistry and cytological evaluation of any fluid obtained often may provide valuable information about the condition affecting the patient.
A minimum database includes: CBC and total proteins including a differential white cell count, chemistry including hepatic enzymes, creatinine, BUN, glucose and electrolytes, and also urinalysis and fecal examination. In some cases, we include more specific tests such as CPL to rule out traumatic pancreatitis which should be considered according with the clinical signs.
When available, radiographic examination of the abdomen may reveal important data and should be part of the diagnosis, monitoring and therapy of any patient with acute abdominal disease. Survey radiographs of the abdomen may reveal pathologic changes within a shorter period of time than the results from many laboratory tests.
Loss of abdominal serosal detail should raise suspicion of free fluid as hemoabdomen or uroabdomen. Free peritoneal air should be interpreted as possible rupture of a hollow organ or a non-detected penetrating injury, as with an animal bite or a projectile wound. In cases where it is necessary to define the integrity of the bladder or the urethra, a pneumocystogram or a positive-contrast cystogram may be used. Some cases with diaphragmatic hernias could be difficult to diagnose, but GI contrast or ultrasound could be used for final diagnosis.
Most of those cases require surgical management after medical stabilization. However, there are controversial reports about no real differences in the outcome of these patients when they are treated only medically compared with surgical. At this time, no definitive recommendations can be done, and each case should be treated individually.
All the penetrating wounds as bites should always be surgically explored. Due to the enormous pressure that animal bites can deliver, internal organs may be affected and the wounds penetrated to the abdominal cavity without being clearly apparent on initial examination.
If a body cavity has been communicated with the exterior because of the bite, and therefore may be contaminated, these areas should be explored thoroughly for underlying tissue damage, followed with careful and gentle cleaning. The surgeon shall decide the need for place drains if dead space is present and also the urgency to perform an open exploration of the abdominal cavity.
Patients that arrive to the hospital with penetrating foreign bodies in place should be sedated and explored. All attempts to remove a penetrating foreign body should be performed under surgical conditions and never be attempted by the owner.
Uroabdomen is a relatively common condition in small animals and may be secondary to blunt trauma or to rupture of the urinary tract due to obstructions. Usually the diagnosis is supported by the physical exam of a depressed animal with vomiting, diarrhea and uremic halitosis. The lack of urination is often another clue reported by the owner.
The finding of free fluid into the abdomen using ultrasound, radiographs or palpation should be followed by the determination of its creatinine and/or potassium levels in the fluid compared with serum. Increased ratios of 1.4 for creatinine and 2.0 for potassium are diagnostics for uroperitoneum.
The treatment is a surgical repair of the damaged structures, previous stabilization of the patient, particularly for the potential hyperkalemia and hypothermia.
Another abdominal emergency is the hemoabdomen or hemoperitoneum, a relatively uncommon emergency in cats compared to dogs. The condition may be caused by different types of trauma: blunt or penetrating. However, in cases with no clear explanation or witnessed trauma, the clinician should remember the possibility of a bleeding neoplasm such as hemangiosarcoma or coagulation disorders. Therefore, a coagulation profile should be recommended as part of their minimum database.
Currently the hemoabdomen caused by trauma is not considered an immediate surgical disease, unless the hemodinamia of the patient cannot be stabilized using fluid therapy with crystalloids, colloids and blood products.
Some recent reports have been presented about a different approach in those patients with active hemoabdomen. This technique is known as 'hypotensive therapy' and the goal is to avoid removing any possible clot formed in the traumatized area by maintaining a subnormal blood pressure with products like fresh frozen plasma (FPP), fresh plasma, or colloids. The endpoint of treatment is a systolic pressure lower than 90 mm Hg or a mean blood pressure lower than 60 mm Hg.
We do not use nor recommend the use of an abdominal bandage placed for the purpose of stopping hemorrhage into the abdomen.
References are available upon request.